.app {
    margin: 0 auto;
    padding: 20px;
    text-align: center;
    font-family: "Microsoft YaHei UI Light", serif;
}

.pattern {
    position: absolute;
    top: 0;
    z-index: 1;
    transition: all .5s;
}

.left {
    left: 0;
}

.right {
    right: 0;
}

.pattern img {
    width: 20vw;
}

.wechat-mask {
    display: none;
    position: fixed;
    left: 0;
    top: 0;
    background: rgba(0, 0, 0, 0.8);
    filter: alpha(opacity=80);
    width: 100%;
    height: 100%;
    z-index: 100;
}

.wechat-mask-icon {
    width: 80ch;
    text-align: center;
    margin-left: 13ch;
    position: relative;
}

.app-icon {
    margin-top: 250px;
    border-radius: 16px;
}

.app-name {
    font-size: 40px;
    letter-spacing: 3px;
}

.download-btn {
    width: 320px;
    border-radius: 40px;
    margin: 50px;
    color: white;
    padding: 12px 46px;
    display: inline-block;
    font-size: 30px;
    letter-spacing: 3px;
    background-color: #32b2a7;
    border: 1px solid #32b2a7;
}

.ios-pro {
    width: 60vm;
    color: blue;
    font-size: 25px;
    letter-spacing: 3px;
}

.ios-des {
    width: 50vw;
    margin: 40px auto 1vw;
    text-align: left;
    justify-content: center;
}

.app-des {
    width: 50vw;
    margin: 40px auto 1vw;
    text-align: left;
    justify-content: center;
}

.des-title {
    letter-spacing: 2px;
    font-size: 30px;
    margin-top: 20px;
    font-weight: bold;
}

.des-body {
    line-height: 1.5;
    letter-spacing: 2px;
    font-size: 20px;
    text-align: left;
    margin: 20px 0 20px 0;
}

.des-link {
    text-decoration: none;
}